Overall aims of the project are to gain greater insight into the physiologic processes associated with post-traumatic respiratory and cardiovascular disorders. A medium sized computer permits repeated simultaneous measurement of cardiac output, oxygen utilization, pulmonary vascular resistance, pulmonary shunting, resting lung volume as well as pulmonary artery, pulmonary wedge and right ventricular pressures. Limb blood flow is simultaneously measured with impedance techniques so that alterations in metabolism of skeletal muscle can be separated from those of the entire body. The complex interrelations between ventilation perfusion and the distribution of peripheral blood flow and oxygenation are under investigation.